In situations like the one Watts found herself in last Thursday, in which a caller alleged to the police that she was having sex in a car in the middle of the day, the practical answer is ... probably not.

Now, it's a little complicated: The ACLU of Southern California is in Watts' corner, saying you do have the right to refuse, while the union representing rank-and-file Los Angeles Police Department officers says you don't have that right, not if you're being detained for questioning.

No one is questioning whether cops have the right to randomly stop pedestrians and ask them to identify themselves. They don't. (Being a motorist is a different legal matter that requires you to provide your license anytime an officer requests it.)

What we're talking about here is a situation like Watts', in which you're stopped by police for the investigation of a specific report of a crime in which you loosely fit a witness' description (been there, done that, by the way).

You can be detained for questioning without that resulting in arrest. However, during such a detention, the LAPD insists citizens have a legal obligation to identify themselves. That's because they have reasonable suspicion you might be involved in a crime.

But ACLU staff attorney Peter Bibring says that you do not have to ID yourself to cops, even if they're investigating a crime and believe you could be involved.

Hector Villagra, executive director of the ACLU of Southern California, issued a statement about the Watts detention:

LAPD’s continued statements concerning an officer’s authority to arrest a person for merely failing to provide identification are not only inaccurate but contrary to law. Without a valid reason to identify her, the officer seems only to have wanted to detain and punish her for exercising her rights.

The LAPD, of course, disagrees. It says it did have a valid reason to identify Watts beyond her refusal to cough up a name or license. Commander Andrew Smith said that once a person is detained for questioning and investigation, he or she is obligated to identify themselves:

Its abundantly clear the that [the first officer to contact Watts] Sergeant [Jim] Parker had a lawful detention based on reasonable suspicion (the standard) on his hands with Ms. Watts and her companion (violation 647a of the penal code). The 911 caller described them, their car and clothing exactly, and also the crime they were committing. So, Parker clearly has a lawful detention, based on reasonable suspicion that a crime is "afoot." Hence their detention. This is not a consensual encounter.

Related Stories

While Villagra of the ACLU said Watts was detained for refusing to identify herself, Smith is arguing that she was technically being lawfully detained for an investigation before the issue of her ID came up. During such an investigation, ID is often the first thing cops will request.

The union that represents LAPD officers, the Los Angeles Police Protective League, issued a citation-rich statement arguing not only that "when you are detained by a police officer, you must provide identification when asked to do so," but that if you refuse, you in fact can be arrested for allegedly obstructing or delaying a cop.

If a detainee will not identify himself, there are several things that officers may do. For one thing, they may prolong the detention for a reasonable time to pursue the matter. As the Court of Appeal observed, “To accept the contention that the officer can stop the suspect and request identification, but that the suspect can turn right around and refuse to provide it, would reduce the authority of the officer to identify a person lawfully stopped by him to a mere fiction.

Officers may also arrest the detainee for willfully delaying or obstructing an officer in his performance of his duties if he refuses to state his name or if he admits to having ID in his possession but refuses to permit officers to inspect it.

Also note that a detainee’s refusal to furnish ID is a suspicious circumstance that may be a factor in determining whether there was probable cause to arrest him.

The L.A. County District Attorney's office, in advice to local law enforcement, says much of the same, stating that "refusal to ID" by a suspect "may violate" the law by "delaying or obstructing official duty."

Sounds fairly airtight to us. Police want to make sure that they aren't dealing with a wanted felon or someone who has a warrant for their arrest.

But ... UC Berkeley law lecturer Charles Denton, a veteran of the Alameda County Public Defender's office, has a slightly more nuanced take. Police and citizens, he said, have clashing rights here: Cops can indeed detain you and take you in to identify you if you're a suspect who's refusing to produce ID. And yet you can refuse to give up your identity, he says:

If you refuse then their recourse is to take you down to the station, take you into custody, figure out how to ID you or take you before a magistrate, and you wouldn't get out until you appear in court.

In this scenario, the result is the same: You're probably going to be identified and, additionally, you might suffer as a result of being locked up temporarily or detained at a police station.

"It's technically wrong that you have to produce ID when they have probable cause," Denton argues, "but the consequences of not doing so are that you will go into custody."

The lawyer says that being detained for questioning and being the subject of probable cause (for arrest) are two different situations, the first not requiring you, at least technically, to ID yourself.

The L.A. police union disagrees, saying even being detained for questioning as part of a specific investigation in which you could be elevated to suspect status means it's time for identification:

What constitutes a lawful detention is also clearly established law for several decades. As the United States Supreme Court ruled in United States v. Sokolow, a person may be detained if there is reasonable suspicion that the detainee may be involved in criminal activity. What is reasonable suspicion is a level of justification considerably less than probable cause for an arrest, and it does not matter that there might be a possible innocent explanation of the activity witnessed by the police officer.

UCLA law professor Paul Bergman, who teaches a "Street Law Clinic," appears to agree:

Once a police officer identifies the suspect as matching a description of people involved in committing a crime, even a low-grade misdemeanor, it gives the police officer the right to do a minimally invasive investigation. And an investigation, typically, even the most minimal investigation, consists of asking for identification. The refusal to provide identification generally gives the police officer the right to investigate further.

As a suspect or even a subject of an investigation, "You do have to comply with a reasonable request for identification," the prof says.

He said refusing to identify oneself to a cop investigating you for even a misdemeanor would, as the police union noted, constitute alleged obstructing or delaying a police officer. "That in itself is a misdemeanor committed in the officer's presence," Bergman said.

He said the right to remain silent does not apply to identifying oneself, either.

Both attorneys seem to agree that refusing to ID yourself when you're the subject of a police investigation will not end well. Denton of Berkeley says:

The practical reality is if you do that you will probably be detained and searched.

L.A. Weekly staff writer Dennis Romero has worked on staff at several magazines and newspapers, including the Philadelphia Inquirer and the Los Angeles Times, where he participated in Pulitzer Prize-winning coverage of the L.A. riots. His work has appeared in Rolling Stone online, the Guardian, and, as a young stringer, the New York Times.